The present invention relates to a method of eliminating or reducing the unauthorized detection and subsequent cloning or unauthorized utilization of electronic serial numbers (ESN) which identify cellular telephones active in a cellular telecommunications network.
Cellular telephones commonly include a controller, such as a microprocessor, electronically coupled to a memory device. The memory stores not only software or programs which govern the operation of the cellular telephone but also an electronic serial number (ESN) that is initially stored in the cellular telephone upon purchase of the phone by a consumer. The ESN or electronic identification or serial number is assigned to that cellular telephone by the entity establishing the cellular telecommunications network. Each cellular telephone is assigned a unique ESN such that when a plurality of cellular telephones are ON or active in the cellular telecommunications net, the network can locate and place a telephone call to a particular cellular or cell phone by broadcasting the ESN of the cell phone throughout the network or a portion thereof.
Cellular telephones also customarily include user activated input devices such as keypads, recall key buttons and associated programs for automatically dialing a telephone number to be called by the cell phone (herein a "called number"). Cellular telephones also commonly include various other buttons which control the cellular communications such as the SEND and the END buttons which initiate and terminate a cellular telephone call.
Also, in customary applications, the cellular telephone logs into the cellular net by initially sending the cell phone's ESN to the cellular telecommunications network. The local antenna for the telecommunications cellular network receives this broadcast ESN number and the central office is then able to locate the cell phone at that particular node or zone in the cellular telecommunications network. Occasionally, such as when an automobile carrying the cell phone enters a tunnel or exits a particular cellular telecommunications node, the cellular phone recognizes that it has lost the telecommunications link with the net or network. The cell phone periodically generates the ESN and broadcasts the ESN to the net in order to reestablish the telecommunications link with the net. This occurs whether the user has established an active telephone communications link (i.e., during a "live" telephone call) or otherwise. In other words, the cell phone, when passing through a tunnel, commonly drops off the telecommunications cellular network. Upon exiting the tunnel, the cell phone, in a periodic manner, generates and broadcasts the ESN number. The telecommunications network picks up that broadcast ESN number and again logs in the cell phone into the network.
Commonly, a similar activity occurs when the automobile carrying the cellular telephone leaves one telecommunications network node or coverage area and there is no overlap between the next telecommunications node or area.
A problem exists in that electronic bandits monitor cellular telephone transmissions of phones leaving tunnels and exiting cellular telecommunication nodes. In particular, in New York City, electronic bandits locate listening devices at the exits of major tunnels. Since all cellular telephones that have previously "logged into" the cell net prior to entrance of the tunnel then attempt to reestablish that telecommunications link upon exiting the tunnel, the electronic listening devices capture valid ESN numbers generated by these cellular telephones as they exit the tunnel. Upon capturing the valid ESN numbers from one or more logged in cellular phones, the electronic bandits then sell and distribute those valid ESN numbers to other individuals. This is customarily done by a further telecommunications link to other criminal conspirators. The criminal conspirators, upon receipt of the "stolen" ESN numbers, then sell those numbers to other individuals who make multiple, unauthorized telephone calls using those cloned or copied ESN numbers. Since the bill to the user arrives sometimes 30 days after the initiation of a telephone call over the cellular network, the user may not discover the unauthorized and illegal cloning and use of the ESN for his or her cell phone for 30 days. As a result, there is a significant theft and unauthorized use of valid ESN numbers from cellular telephones in major metropolitan areas.